1. Field of the Invention
The present invention relates generally to an axial load pumping apparatus and, more particularly, to a thrust bearing used in a high axial load pumping apparatus.
2. Description of the Prior Art
High axial load horizontal pumps operate at rotational speeds of approximately 3600 revolutions per minute (rpm). While operating at such high rpm, the horizontal pump must also be able to bear a high load, typically ranging from 4,000 pounds to 8,000 pounds. To protect the motor driving the pump, the thrust bearing assembly is staged on the shaft to absorb the thrust. Unfortunately, at the high speed of operation typically found in such a horizontal pump, bearings used to carry the thrust load wear out quickly and thus have a short life span. Thrust bearing failure is a common problem because of the extreme conditions to which the bearings are subjected.
One solution to providing thrust bearings that can carry the load is to use a multiple bearing assembly with load sharing devices. The load sharing bearings that are normally used in such a situation must rely on precision machined bearing retainers and are limited in operational speed. Further, these particular bearings are very sensitive to tolerances and assembly errors as well as being very expensive.
Further, the thrust bearings must be lubricated during operation to protect them from the high temperature and stress to which they are subjected. Since an overall bearing assembly is compact in design, a path for lubrication is difficult to provide and lack of proper lubrication leads to shorter life expectancy due to high pressure and high temperatures.
Accordingly, what is needed is a thrust chamber bearing apparatus that is better able to transfer the load from the shaft to the thrust bearings and subsequently to the housing without requiring the precision machine bearing retainers typically used. Further, what is needed is a way of lubricating the thrust bearing assembly in such a way as to optimize lubrication and to reduce the operating temperature of the bearings.